Preterite vs imperfect
The short answer
The preterite reports a completed event that moves the story forward. The imperfect describes the situation around it: background, habits, and actions already in progress. If the sentence answers “what happened next?”, use the preterite; if it answers “what was it like?”, use the imperfect.
At a glance
Preterite or Imperfect?
| Compare | PreteriteA completed event. Moves the story on. | ImperfectThe situation around it. Sets the scene. |
|---|---|---|
| What it does | Reports an event | Describes the background |
| Boundaries | The action starts and finishes | No start or finish in view |
| Repetition | Once, or a stated number of times | Habitually: used to, would |
| Two actions at once | The one that interrupts | The one already in progress |
| Typical markers | ayer, anoche, de repente, una vez, en 2019 | siempre, todos los días, mientras, cuando era |
| Age, time, weather | Rarely | Usually: tenía diez años, eran las tres |
How to choose
Ask these, in order
- 1
Could you follow it with “and then what?”
Preterite. It is an event with an end.
Abrió la puerta y salió sin decir nada.
She opened the door and left without saying anything.
- 2
Is it describing the scene, weather, age, time, mood, appearance?
Imperfect.
Era de noche y hacía mucho frío.
It was night and it was very cold.
- 3
Did it happen repeatedly, with no number attached?
Imperfect. This is the “used to” of Spanish.
Los domingos íbamos a casa de mi abuela.
On Sundays we used to go to my grandmother’s.
NBAdd a number, fuimos tres veces, and it becomes a counted event.
- 4
Was one thing already going on when another happened?
Imperfect for the one running, preterite for the one that cuts in.
Dormía cuando sonó el teléfono.
I was asleep when the phone rang.
Side by side
Each one, in full
When to use the preterite
A completed event. Moves the story on.
The preterite reports. Each verb in it is something that happened, finished, and let the next thing happen, which is why a run of preterites reads as narrative and why it answers “what did you do yesterday?”.
A stated duration counts as a boundary: viví en Sevilla durante tres años takes the preterite even though three years is long. Length has nothing to do with the choice; having an end does.
Ayer perdí el tren.
I missed the train yesterday.
Estudiaron toda la noche y aprobaron.
They studied all night and passed.
Llovió tres veces esta semana.
It rained three times this week.
NBWeather usually takes the imperfect, but a counted number of occasions makes it an event.
When to use the imperfect
The situation around it. Sets the scene.
The imperfect describes. It gives the state of things: weather, time, age, mood, what was already under way, without asking when any of it started or whether it has stopped.
It also carries habit, and it is the ordinary Spanish for the English “used to” and past habitual “would”. Cuando era pequeño, jugaba al fútbol covers both readings with one tense.
Tenía veinte años y vivía con sus padres.
She was twenty and living with her parents.
Siempre llegaba tarde a las reuniones.
He always used to arrive late to meetings.
Mientras cocinaba, escuchaba la radio.
While she cooked, she listened to the radio.
Mistakes to avoid
What learners actually get wrong
Cuando era niño, jugué al fútbol todos los sábados.
Cuando era niño, jugaba al fútbol todos los sábados.
Todos los sábados makes it a habit with no fixed number of occasions, so it takes the imperfect. The preterite would say you played on a countable set of Saturdays and then stopped.
Vivía en Madrid durante cinco años.
Viví en Madrid durante cinco años.
Durante cinco años closes the period, so it needs the preterite. Using the imperfect leaves the stay open-ended, contradicting the boundary the sentence has just supplied.
Cuando vi su cara, sabía inmediatamente.
Cuando vi su cara, supe inmediatamente.
Saber in the imperfect means knew as a standing state; in the preterite it means found out, at a moment. Inmediatamente marks that moment. Conocer, querer and poder shift the same way.
Había un accidente en la esquina.
Hubo un accidente en la esquina.
An accident is an event, not a scene. Había un accidente describes a situation you arrived to find; hubo un accidente reports the crash happening. English “there was” covers both and Spanish does not.
Questions
Asked and answered
- Is this the same distinction French makes?
- Almost exactly. The preterite corresponds to the passé composé and the imperfect to the imparfait, including the meaning shifts with know, want and be able to. If you have studied French, this transfers with very little adjustment, the main difference is that Spanish keeps a simple preterite where French uses a compound tense.
- Which verbs change meaning between the tenses?
- Four matter. Saber: sabía is knew, supo is found out. Conocer: conocía is knew someone, conoció is met them. Querer: quería is wanted, quiso is tried and quiso is refused in the negative. Poder: podía is was able, pudo is managed to.
- Can both appear in one sentence?
- Constantly, and that is the normal case. The imperfect lays out the situation and the preterite reports what happened in it: llovía cuando salí. Neither tense alone would carry the sentence, which is why they are best practised together rather than one at a time.